Another point in favor of 60 is there are 60 seconds in a minute and 60 minutes in an hour. If you make the frequency 60 cycles/second then you only need divide

Another point in favor of 60 is there are 60 seconds in a minute and 60 minutes in an hour. If you make the frequency 60 cycles/second then you only need divide-by-60 circuits to derive 1 cycle/second, 1 cycle/minute, and 1 cycle/hour. With 50 cycles/second you would need both divide-by-50 and divide-by-60.